Untitled

## app/moodels/user.rb
require 'digest/sha2'
class User < ActiveRecord::Base
  def password=(pass)
    salt = [Array.new(6){rand(256).chr}.join].pack("m").chomp
    self.password_salt, self.password_hash =
      salt, Digest::SHA256.hexdigest(pass + salt)
  end
end


require 'digest/sha2'
class User < ActiveRecord::Base
  validates_uniqueness_of :username

  def self.authenticate(username, password)
    user = User.find(:first, :conditions => ['username = ?', username])
    if user.blank? ||
      Digest::SHA256.hexdigest(password + user.password_salt) != user.password_hash
      raise "Username or password invalid"
    end
    user
  end
end

## apps/controllers/welcome_controller

class WelcomeController < ApplicationController
before_filter :check_authentication, :except => [signin]

  def check_authentication
    unless session[:user]
      session[:intended_action] = action_name
      session[:intended_controller] = controller_name
      redirect_to :action => "signin"
    end
  end

def signin
session[:user] = User.authenticate(params[:username], params[:password]).id
redirect_to :action => session[:intended_action],
:controller => session[:intended_controller]
end

end

## app/views/welcome/signin.html.erb

<html>
<head>
<title>Signin for Admin Access</title>
</head>
<body>
<%= start_form_tag :action => "signin" %>
<label for="username" >Username:</label>
<%= text_field_tag "username" %><br />
<label for="password" >Password:</label>
<%= password_field_tag "password" %><br />
<%= submit_tag "Sign in" %>
<%= end_form_tag %>
</body>
</html>